Pareiasaurs Fossil range: Middle Permian–Late Permian PreЄ Є O S D C P T J K Pg N
Scutosaurus karpinskii from the Late Permian of Russia
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Sauropsida
Subclass:	Anapsida
Order:	Procolophonia
Family:	Pareiasauridae Lydekker, 1889
Genera
Arganaceras Bradysaurus Nochelesaurus Embrithosaurus Deltavjatia Velosauria Shihtienfenia Pareiasuchus Pareiasaurus Scutosaurus Elginia Nanopareia

The Pareiasaurs - Family Pareiasauridae - are a clade of medium-sized to large herbivorous anapsid reptiles that flourished during the Permian period.

Their build was quite stocky, often with rather short tails and small heads. These ungainly-looking animals had very large bodies, ranging from 60 to 300 centimetres (2.0 to 9.8 ft) long, and weights of 600 kilograms (1,300 lb) would not been unusual. They also had strong limbs, broad feet, and short tails. They were protected with bony scutes (osteoderms) set in the skin, as a defense against predators. Their heavy skulls were ornamented with multiple knobs and ridges.

Deltavjatia vjatkensis

The leaf-shaped multi-cusped teeth resemble those of iguanas, caseids, and other reptilian herbivores. This dentition, together with the deep capacious body, which could have housed an extensive digestive tract, indicate that these fearsome-looking animals were herbivores.

Lee (1997) has argued that pareiasaurs evolved into turtles. They had turtle-like skull features, and in several genera the scutes had developed into bony plates, possibly the precursors of a turtle shell. However, critics have pointed out problems in this view, such as the lack of homology between pareiasaur scutes and the turtle shell.

[edit] In popular culture

In Edgar Rice Burroughs' novel Tarzan at the Earth's Core, the characters encounter pareiasaurs in Pellucidar. They are called Gorobors by the native Pellucidarians. In the book they are portrayed as the fastest of all animals.

The British ITV show Primeval shows pareiasaurs in several episodes, though these pareiasaurs are shown being the size of elephants, much larger than the actual creature. Though it is possible that an yet undescribed genus or species of pareiasaurs grew to this size, this is somewhat unlikely.

[edit] References / Links

This article includes a list of references, related reading or external links, but its sources remain unclear because it lacks inline citations. Please improve this article by introducing more precise citations where appropriate. (April 2009)

• Carroll, R. L., (1988), Vertebrate Paleontology and Evolution, W.H. Freeman & Co. New York, p. 205
• deBraga, M. & Rieppel, O. (1997) Reptile phylogeny and the interrelationships of turtles, Zool. J. Linnean Soc. 120: 281-354.
• Kuhn, O, 1969, Cotylosauria, part 6 of Handbuch der Palaoherpetologie (Encyclopedia of Palaeoherpetology), Gustav Fischer Verlag, Stuttgart & Portland
• Laurin, M. (1996), "Introduction to Pareiasauria - An Upper Permian group of Anapsids"
• Lee, M.S.Y. (1997), Pareiasaur phylogeny and the origin of turtles. Zool. J. Linnean Soc., 120: 197-280
• Mikko's Phylogeny Archive Hallucicrania - Pareiasauriformes
• Palaeos Anapsida: Hallucicrania